Research review: Vitamin D may prevent tooth decay

By Michael Johnsen

SEATTLE — A new review of existing studies points toward a potential role for vitamin D in helping to prevent dental caries, or tooth decay. The review, published in the December issue of Nutrition Reviews, encompassed 24 controlled clinical trials, spanning the 1920s to the 1980s, on approximately 3,000 children in several countries. These trials showed that vitamin D was associated with an approximately 50% reduction in the incidence of tooth decay, the University of Washington announced Tuesday.

"My main goal was to summarize the clinical trial database so that we could take a fresh look at this vitamin D question," stated Philippe Hujoel of the University of Washington, who conducted the review.

While vitamin D's role in supporting bone health has not been disputed, significant disagreement has historically existed over its role in preventing caries, Hujoel noted. The American Medical Association and the U.S. National Research Council concluded around 1950 that vitamin D was beneficial in managing dental caries. The American Dental Association said otherwise – based on the same evidence. In 1989, the National Research Council, despite new evidence supporting vitamin D's caries-fighting benefits, called the issue "unresolved."

Current reviews by the Institute of Medicine, the U.S. Department of Human Health and Service and the American Dental Association draw no conclusions on the vitamin D evidence as it relates to dental caries.

"Such inconsistent conclusions by different organizations do not make much sense from an evidence-based perspective," Hujoel said. The trials he reviewed increased vitamin D levels in children through the use of supplemental UV radiation or by supplementing the children's diet with cod-liver oil or other products containing the vitamin.

Hujoel added a note of caution to his findings: "One has to be careful with the interpretation of this systematic review. The trials had weaknesses which could have biased the result, and most of the trial participants lived in an era that differs profoundly from today's environment. "